Process of treating ores preparatory to magnetic separation.



J. B. ETHERINGTON. PROCESS OF TREATING ones PREPARA'IORY T0 MAGNETIC SEPARATION.

APPLICATION FILED APILG, 1912. 1,053,486. Patented Feb. 18, 1913.

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IVIAGNETIC SEPAR ATING (JOMIPAN'TJ,

rimcnssor TREATING onus "1b all whom 22* may concern Be it known that l. Janus ll l l'rnmnsc- TON, a citizen of the lnited States. residing! at W'inthrop, in the rountyot feuilolh and Siate of Massachusetts. have invented new a d useful Improvements in Proves-w ol' Treating Ores lreparatory to i .ltlfl'!l(lii' $eparation, of which the following is a specification. This invention relates to the treatment of ferruginous ores containing suifids. being a division of my copending application filed Jan. 12, 1911. Serial No. 602.177.

The invention consists in a. process the object of which is to render such ores susceptible tomagnetic or electrical influences without volatilizing or matcn'ia'lly oxidizing? the metallic constituents.

My process consists primarily in heatin;- the ore in a furnace, containing a ncn-oxidizing atmosphere or an atmosphere pos- .sessing a minimum amount of free oxygen.

I have discovered that in order to get the best results'in magnetizing non-magnetic ores by heat, it is desirable to admit only sufficient air to support the combustion of the fuel, without materially oxidizing the metallic constituents of the ore.

' Iain aware that, prior to my invention, it was discovered that the ferruginous constituent in non-magnetic pyrititerons ores containing in addition to the iron other base or recious metals could be magnetized by sub ecting the same to heat for a brief time without removing substantial port ons of any of the solid constituents of the ore; and that Letters Patent were granted for such process to Henry F. Campbell, No. 723,363, dated March 24. 1903, which invention i. am utilizing, in the herein described process, to the greatest practical and. commercialad- Prior to my invention, it was the general practice to roast sulfidv ores for a number of hours while freely exposed to oxidation, in order to render them magnetic, employ ing therefor costly and pcnderous apparatus, and producing wasteful results. l ly means of my process, employing in the practice of the same comparatively light and inexpensive apparatus, I am able to treat nonmagnetic pyritiferous ores commercially and economically so as to render the terruginous Specification of Letters Patent.

. 0r'iginalvapplicaticn filed January 12. 1911., Serial. No. 602.177.

1912. Serial No. 638.938,

A. CORPORATION OF ARIZONA.

IPll-tEPARATORY TO MAGNETIC SEPARATION.

Patented Feb. 18. 1913. Divided and this appdicatiqn filed April 6,

constituents nlagnetichy subjecting said ores to heat for a few minutes. i The principal feature of my process constats. in conveying the ore through a furuaru. into which is blown a llama created outside the furnace, and carrying witlritx. into the furnace practically only sullicient air to support the combustion of the'fuel in the blast, thereby preventing any considerable oxidation of the ore. This is contrary to the former methods. Ilere'tofore it has been a common practice to roastthc ore in a furi'iace o'r roaster with an abundamro of air circulating thrtn'lgh it, in order to oxidize full} and as rapidly as possible the sulfur of the ore. thereby converting-the: iron into an oxid. The tire was built and run inside of the roaster and depended upon a free draft of air through the roaster to maintain it. There were no means, nor any attempt to provide means, to limit the supr ply of air, but on the contrary, to furnish the maximum amount of orygen to the ore, was considered indispensable to good results. The dili'crence between the prior art methods and my process is radical in this respect.

My invention resides in heating the ore while exposed to the minin'nnn amount of oxygen. The prior art consists in exposing the ore to the maximumamount of oxygcnfi while roasting i.

My invention is not limited to heating in a strictly reducing or non-oxidizing atmos phere, but includes one that approximates it. by possessing a minimum amount of; mtyg'en which acrrmplishes the essentialobjccts of my invention. .Vhenever I make use of the terms non-oxidizing or reducing atmosphere, they shall be understood to include conditions under which the ore J while being heated is *xposed to a minimum amount of oxygen.- in the methods of roasting ore, prior to my invention, the heat was not applied: to the ore with such precision and uniformity that any reliance could be placed upon magnetizing the ore that passed through the furnace, without excessively roasting a large percentage of it, and actually fusing some of its constitutents. There were two serious evils in the apparatus and methods of the prior art, namely,

sulfid retains such a large \Vhen sulfid ores, either low or high grade, containing iron sulfids and zinc sulfids alone, or combined with other metals,

are treated by my process, and then subjected to magnetic separation, the products are a zinc sulfid containing a minimum amount of iron, and an iron sulfidcontaina minimum amount of zinc. The 11011 percentage of its original sulfur as to make it a valuable commercial product.

ing

My. invention is applicable to all kinds of q ores containing iron and other base and from 30 to inches in i the cylinder precious metals which require treatment to make them susceptible or more susceptible to magnetic influences.

The means heretofore employed by me for practising my process, which have proved to be eflicient are shown in the accompanying drawing in which- Figure 1 is a side elevation ofthe same; Fig. 2 is a diagrammatic view illustrating the heat generators and the interior of the larger section of the furnace; and Fig. 3 is an elevation of the discharging end of the furnace.

I Referring to the drawing, 4 is an unlined .metallic cylinder mounted and rotated in any manner well known in the art for mounting and rotating roasters of various descriptions. This cylinder 4 may be made diameter and of plate iron about of an inch thick.

5 represents a cylinderof similar matej r taming non-magnetic zinc and ironsulfids,

rial, but longer and of smaller diameter, which is bolted to the head of the cylinder 4, and connects it with the flue either directly or through any suitable dust arreste'r.

6 is a hopper for feeding the ore into the furnace, from which it is caused to travel through the furnace by reason of the inclination and rotary motion thereof. Theore is met in the cylinder 4 by the flame from a hydrocarbon burner 7, located outside of heat are projected by a blast of airsu'pplicd and regulated by said burner in the familiar way. For my purpose, I prefer to use the set my hand in witnesses, 4, into which the flame and type of burner shown in the United States atent to Barker, 10th, 1906. But any either fuel oil, coal gas, or the like, and capableof producing a jet of flame when projected by a blast of air into the retort, will suffice for my purposes. Thesmall ports 8 for the discharge of the ore in the head 9 (see Fig. 3) are not of sufiicient area to admit an appreciable amount of air, and no air enters them except as a result of the artificial blast of air from the burner, be cause without the latter, the pressure of air and gases is outward from the furnace." I find, therefore, that the construction shown enables the operator to predetermine the volume of air admitted to thefu'rnace and to control and regulate it so as to maintain practically a reducing or non-oxidizing atmosphere in the furnace.

In Fig. 2 the arrows show the course of the flame and heat projectedfrom the burner. While I have shown but one burner,

No. 825,290, issued July burner, employing two or more may be employed, as preferred.

The means shown are only one of man'ythat may be devisedto practise my processfand they are shown simply but not to limit in any manner the-scope of the invention.

.What I claim and desire to secure by Letters Patent is:

1. The process of treating ore, containing non-magnetic iron sulfids,

the'action of the heat.

2. The process of treating ore, containing. non-magnetic iron sulfids,

same to heat in a reducnig at consisting of subjecting the mosphere until the iron sulfide become magnetic, and then removing the same from the action of heat before the iron sulfids are converted into OXldS-' .3. The process of concentrating ores, conconsisting of subjecting the same to heat In a non-oxidizing atmosphere until the iron sulfids become magnetic, then removing the ore from the action 3f heat into oxids, and then magnetically; senarat-ing. the same;

converted In testimony whercofjI have hereunto presence of two subscribing this 18th day ofMarch 1912. JAMES B. ETHERINGTON. Witnesses:

J OHN F. PERKINS,

-Lou1s ALLEN.

consisting of siib jecting the same to heat in a non-oxidizing atmosphere until the iron sulfids become magnetic, and then removing the same from} to illustrate 'onewa'y 

